ARCHIVED: What is ROT13?

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ROT13 is a very simple code that scrambles text so that it is not readable. It works by converting a letter into the letter that is 13 away from it in the alphabet, wrapping to the beginning when going beyond the end of the alphabet. The following table shows what letters become what:

  a <--> n
  b <--> o
  c <--> p
  d <--> q
  e <--> r
  f <--> s
  g <--> t
  h <--> u
  i <--> v
  j <--> w
  k <--> x
  l <--> y
  m <--> z

ROT13 was designed for use in Usenet newsgroups as a way to hide the content of postings. For example, a person could use ROT13 to encode an article he thinks may be offensive to some. That way, those who would be offended can pass the message over without having to see it, while others can use their ROT13 decoders (built into most newsreaders) to read the post. Another way ROT13 has been used is scrambling email addresses in the contents of news articles, making it difficult for Internet spammers to steal the addresses.

Note: ROT13 is not at all secure. Anyone with a ROT13 decoder can read text encoded with ROT13.

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Last modified on 2018-01-18 12:09:13.